Blade with 3D platform comprising an inter-blade bulb

A blade for a turbomachine impeller, comprising:

• an airfoil including a pressure surface, a suction surface, a trailing edge, and a leading edge;
• and
• a platform extending at one of the ends of the airfoil in a direction which is globally Perpendicular to a longitudinal direction of the airfoil,
• wherein the blade is adapted to be arranged with a plurality of substantially identical blades to form a ring around a ring axis and define therealong upstream and a downstream area, with the ring having the airfoils arranged substantially radially therein, and the adjacent blade platforms joining in pairs so as to form an inter-airfoil surface linking the pressure surface of an airfoil to the suction surface of the neighboring airfoil,
• wherein in an upstream half of the airfoil, only a single boss is formed on the inter -airfoil surface, the boss being located closer to the pressure surface than to the suction surface, and a recessed passage is located between the boss and the pressure surface,
• wherein the inter-airfoil surface comprises a part of revolution having a shape of revolution with respect to the ring axis, located on a side of the suction surface of the airfoil neighboring the boss,
• wherein the boss is linked to the part of revolution by a radially descending surface, and
• wherein the boss occupies a majority of the portion of the inter-airfoil surface which extends in a circumferential direction from the pressure surface of the airfoil to the suction surface of the neighboring airfoil and axially from 0% to 50% of an axial extent of the airfoil from the leading edge of the airfoil;
• wherein the boss includes an apex located axially between 0% and 25% of the airfoil on the upstream side.